The Benefits of Computer Viruses

I know many people have had huge inconveniences from viruses and malware. I have spent many hours dealing with the consequences myself. But sometimes I wonder if in the end, maybe it's for the best? Imagine if we had built up the kind of infrastructure we have today without the constant threat of malicious code. A determined attacker would be able to wipe out the entire internet and everyone on it. Like a child who has never been exposed to mild colds, we would be at risk of fatal illness and be utterly unprepared.